The present invention relates to an electrical coupling device for use in an electrical junction box to connect electrical wires together.
Various electrical coupling devices are known and widely used to connect electrical wires in an electrical junction box or panel. FIG. 1 shows an electrical coupling device according to the prior art, which is generally comprised of a wiring block directly having unitary stands fastened to the electrical junction box or panel and having index strips at two opposite sides, and a plurality of connecting block assemblies respectively fastened to the index strips to join conductors. This electrical coupling device is not satisfactory in function because it is not expansible. For example, if the electrical coupling device comprises four sets of connecting block assemblies and each connecting block assembly is made to couple 25 sets of electrical wires, the electrical coupling device can then couple 100 sets of electrical wires maximum. When there are more than 101 sets of electrical wires to be matched, at least two electrical coupling devices must be used. If there are only few sets of electrical wires to be matched, much vacant spaces will be left for no use. Another drawback of this structure of electrical coupling device is that the electrical coupling device cannot be conveniently dismantled from the electrical junction box or panel when installed, causing the maintenance and inspection works difficult to perform.
There is also known a detachable structure of electrical coupling device which, as shown in FIG. 2, is generally comprised of a wiring block and two supporting block fastened to the two opposite ends of the wiring block at the bottom. The wiring block has two rows of upright posts with mounting holes. The supporting blocks have a respective pair of hooked members at the top. When connected, the hooked members engage the two opposite outer upright posts at either end of the wiring block by hooked joints. This structure of electrical coupling device permits the wiring blocks to be removed from the supporting blocks when the hooked members are released from the respective upright posts, and therefore the maintenance and inspection works can be conveniently performed. However, this structure of electrical coupling device still has drawbacks. When two wiring blocks are connected in parallel by two supporting blocks, the two hooked members of either supporting blocks must be respectively fastened to one upright post on either wiring block at either end. This arrangement cannot keep the wiring blocks stably maintained in place, and the hooked members may disconnect from the wiring blocks easily.